Author Topic: Ares I Thrust Oscillation meetings conclude with encouraging data, changes  (Read 153487 times)

Offline kyle_baron

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That's exactly my point.  I realize that T.O. will always be part of a SRM.  However, the "shake its passengers to death" requires additional inputs (similar frequencies) from the rest of the rocket.  IMO, the similar frequencies will not happen, because the stages and interfaces, have different materials, all vibrating at different frequencies.

It will not happen because we will not allow it to happen. You can't sit back and think 'oh, it will never happen' because then it surely does.  I intend to make sure it does not happen by putting this specific environment (and several others of similar concern) in the SRD of this new vehicle.

Ok, No arguement here.  Remember, I did say it was my opinion.  ;)
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Offline kyle_baron

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IIRC, the Orion capsule had a mass margin of only .5 ton on Ares 1.  With Friction-Stir welding on the 2nd stage propellent tanks, that adds approximatly 3.5 tons, for a total of 4 tons.  This 4 ton margin doesn't include astronauts, or any T.O. mitigation hardware.

I figure the astronauts at 200 lbs. each X 4 = 800 lbs.  The LOX Bellows at 314 lbs.  Does anyone want to guess the mass of the C-Spring Module?  I'm guessing at least 1000 lbs (.5 ton).  This would leave Orion with a 3 ton margin for supplies, or additional features that were removed in the zero based design.
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Offline FinalFrontier

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Even if they fixed it some points remain valid:

1. Ares 1 costs an obscene amount of money to develop and would cost alot of money for each mission (each new rocket).
2. If they must add new parts or modules to fix the issue then they are adding weight further reducing preformance (and its not great as it is since ares 1 cannot actually put orion in orbit (the sm engine must complete the launch burn))
3. Whatever they add requires additonally R&D perhaps an additional test flight and it adds money in and of itself.
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Offline Jim

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I figure the astronauts at 200 lbs. each X 4 = 800 lbs. 

For the shuttle, it is 450 lbs per crew.

Offline kyle_baron

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Even if they fixed it some points remain valid:

1. Ares 1 costs an obscene amount of money to develop and would cost alot of money for each mission (each new rocket).
2. If they must add new parts or modules to fix the issue then they are adding weight further reducing preformance (and its not great as it is since ares 1 cannot actually put orion in orbit (the sm engine must complete the launch burn))
3. Whatever they add requires additonally R&D perhaps an additional test flight and it adds money in and of itself.


1.  Of course it will cost a lot of money to develope, test, and qualify. IT'S A BRAND NEW ROCKET.  IIRC, the cost of each mission is only $200-$500 million, and it will be, the safest rocket.
2.  There is plenty of mass margin for the T.O. mitigation, as I stated previously,with the new friction-welding process.  The SM engine will have enough propellent for LEO and EOI.
3.  Maybe, but over the 30-40 yr. life span of the program, that's small peanuts.
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Offline kyle_baron

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I figure the astronauts at 200 lbs. each X 4 = 800 lbs. 

For the shuttle, it is 450 lbs per crew.

Those are some fat astronauts!  (I know what you're really saying).  ;)
That still will leave a 2.5 ton mass margin.
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Offline Jim

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1.  Of course it will cost a lot of money to develope, test, and qualify. IT'S A BRAND NEW ROCKET.  IIRC, the cost of each mission is only $200-$500 million, and it will be, the safest rocket.
2.  There is plenty of mass margin for the T.O. mitigation, as I stated previously,with the new friction-welding process.  The SM engine will have enough propellent for LEO and EOI.
3.  Maybe, but over the 30-40 yr. life span of the program, that's small peanuts.

1. That is not a guarantee.  It may have one of the better calculated  design reliability but that doesn't mean it translates into real numbers.  The little increase in reliability is not worth the development costs

2.  No, the final numbers haven't come in yet.  The friction-welding numbers may be high.

3.  It isn't going to last 30-40 years, much less 20.  that is another issue.

Offline texas_space

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I figure the astronauts at 200 lbs. each X 4 = 800 lbs. 

For the shuttle, it is 450 lbs per crew.

Does that number include the reentry suits mass as well or is that a separate allotment?
"We went to the moon nine times. Why fake it nine times, if we faked it?" - Charlie Duke

Offline Jim

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I figure the astronauts at 200 lbs. each X 4 = 800 lbs. 

For the shuttle, it is 450 lbs per crew.

Does that number include the reentry suits mass as well or is that a separate allotment?

Everything associated with adding another crew member, food, O2, seat, clothing, etc

Offline texas_space

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Thanks for the answer Jim!
"We went to the moon nine times. Why fake it nine times, if we faked it?" - Charlie Duke

Offline kyle_baron

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Thanks for the answer Jim!
I'll 2nd that.  Thank you Jim, for your opinions, concerning my statements.
« Last Edit: 12/30/2009 05:49 PM by kyle_baron »
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Offline JohnFornaro

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Just to help my understanding:

Food and O2 for how many days?  Are the oxygen tanks not included?
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Chuck and others bring up the apparently continued lack of solution to the TO problem.  Is there an update?

... this appears to be Danny's data, not released directly by NASA....
Sometimes I just flat out don't get it.

Offline renclod

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(Image removed due to patent pending - Chris).
« Last Edit: 10/04/2010 04:17 PM by Chris Bergin »

Offline Ben the Space Brit

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Just to help my understanding:

Food and O2 for how many days?  Are the oxygen tanks not included?

This is only a guess on my part.  However, I would imagine that NASA's early calculations are for the three to four days for an ISS crew rotation mission.
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Offline renclod

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It looks like development of the "LOX Damper" stems from efforts to understand the physics of intriguing simulated propellant slosh damping observed in experiments at NASA MSFC.



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